A BBC2 experiment on the power of plants has left Professor Iain Stewart suffering from blinding headaches

Professor Iain Stewart suffered blinding headaches during a BBC2 experiment
testing the power of plants.

Stewart, professor of geoscience at the University of Plymouth, sealed himself
in an airtight ‘bell jar’ with only plants for company, in a bid to
demonstrate their oxygen-giving effects.

After the oxygen levels in his tank were reduced, Stewart’s ability to breathe
depended on 150 plants, which absorb carbon dioxide and release oxygen. For
this reason, plants are dubbed ‘the lungs of the planet’.

He told BBC Radio Five Live: “I went into the chamber at 10pm on Thursday
night and immediately what we did was take the oxygen levels from 21%, which
is normal, to 12.5%.

“Then a whole bank of lights were turned on and the plants inside the chamber
started to synthesise and they started pumping out oxygen for me to breathe.”